Method for wet-treating, in particular cleaning, objects

ABSTRACT

When treatment liquid is re-used for washing objects, first of all there has to be a test as to whether the concentration of the at least one treatment additive in the used treatment liquid is sufficient. Up to now all the treatment liquid to be re-used has been measured for this purpose. If it is necessary for the measuring to filter solids, which influence the measuring, out of the treatment liquid beforehand, all the treatment liquid to be re-used has to be filtered. This requires a correspondingly efficient filter. 
     The invention provides for branching off a small amount from the treatment liquid to be re-used as a sample and only measuring said sample with regard to the concentration of at least one treatment additive still present in the used treatment liquid. Only a small part of the treatment liquid to be re-used serving as a sample has then to be filtered prior to the measuring process. Only a relatively small filter is necessary for this purpose. The measuring of the sample which only has a small amount of treatment liquid is able to be effected in a simpler and more reliable manner.

The invention relates to a method for wet-treating objects preferably in a washing device as claimed in the preamble of claim 1.

Above all in the industrial sector, different objects have to be subject to wet treatment, in particular washing. The invention relates to wet-treating, in particular washing, objects of all types, in particular the wet-treating of garments, the washing of containers, in particular the washing of containers for foodstuffs, the washing of bottles and washing systems for all kinds of vehicles and industrial devices, for example, conveyor belts.

Treatment liquid which has at least one treatment additive is used in the case of the wet-treatment of objects. From an environmental perspective, attempts are made to use the treatment liquid multiple times because even used treatment liquid still has unused treatment additives. A prerequisite for the re-use of used washing liquid, however, is that it still has sufficient treatment additives so that the objects to be treated next can be treated, in particular washed, to a sufficient extent.

It is known to measure the concentration of at least one treatment additive which is still present in the treatment liquid prior to the re-use of the treatment liquid in order to be able to ascertain whether the at least one treatment additive in the treatment liquid is sufficient for the re-use of the same. Where necessary, as a result of the measuring, the relevant treatment additive can be additionally metered in a targeted manner prior to the re-use of the treatment liquid. The measuring of the at least one treatment additive has been effected up to now quasi “online” in the overall stream of the treatment liquid. This has proved to be unfavorable in practice.

The object underlying the invention is to create a method for wet-treating objects preferably in a washing device, by way of which method it is possible to measure the treatment liquid in a simpler manner.

This object is achieved by a method with the measures of claim 1. Accordingly, it is provided preferably to branch off a small amount from the treatment liquid used and to be re-used as a sample and to measure only said sample. Thus it is no longer necessary to measure all the treatment liquid. As a result, it is possible to use a simple measuring technique which is set up for small sample amounts. After measuring, where applicable the small sample amount can be simply disposed of.

The method can be further developed such that the sample is filtered prior to the measuring, for example micro-filtration of the sample is preferably effected. The filtration of the sample, however, can also be effected in another manner and, where applicable, also in multiple steps. The method can be simplified through the filtration of only small sample amounts. It is possible, in particular, to measure in a reliable and more accurate manner in this way. Because the sample only includes a small amount of treatment liquid, all the treatment liquid does not need to be filtered prior to the measuring. The filtration of the sample containing only a small amount of liquid can be carried out rapidly and economically. The sample can also be filtered using filtration methods which operate in a relatively slow but reliable manner.

In a preferred manner, the method provides for the sample being branched off from the used treatment liquid, preferably prior to the re-use of the same. This can be effected “in situ”. As the treatment liquid is separated from the objects to be treated prior to the re-use, the sample of the treatment liquid can be measured simply outside the washing device. As a result of the sample being branched off from the treatment liquid prior to the re-use, the measuring process supplies measurement results which convey the state of said treatment liquid in a timely manner prior to the re-use of said treatment liquid. As a result, the treatment liquid is able to be influenced, for example by the addition of at least one treatment additive before the treatment liquid once again serves for the wet-treating of objects.

An advantageous development of the method provides that the sample of treatment liquid to be re-used is taken after said treatment liquid has been returned again into the washing device and/or into a preparation tank for preparing the treatment liquid to be re-used for use in the washing device. Said method of operation ensures that the treatment liquid is measured in the state in which it is re-used, with regard to the desired properties. In particular when the treatment liquid to be re-used is mixed from differently used treatment liquids or from both used and non-used treatment liquids, the mixture created thereby can be tested by means of the afore-described measuring process for its suitability directly prior to the treatment of objects to be washed.

In addition, in a preferred manner it is provided that the sample is branched off from the treatment liquid and/or measured during the operation of the washing device. In this way, it is possible to ascertain the state of the treatment liquid at a suitable point in time. For example, it can be determined in this way whether sufficient active washing substances are still present in the used treatment liquid.

A preferred development of the method provides for determining the remaining proportion of the at least one treatment additive in the used treatment liquid and for additionally metering the relevant treatment additive if a minimum proportion of the at least one treatment additive in the treatment liquid is undershot. In this way, it is ensured that even the re-used treatment liquid still has a sufficient proportion of the at least one treatment additive which is sufficient for washing the objects with the re-used treatment liquid.

After the single or after each additional metering of the treatment liquid to be re-used, a small sample hereof is preferably taken and measured once again. In this way it can be ascertained whether the additional metering was sufficient. Where applicable, through several targeted additional meterings it can be determined in a successive or iterative manner whether the additional metering is sufficient, and in this way the additional metering is performed in a targeted manner without resulting in excessive additional metering.

A preferred development of the device provides for determining the proportion of the active cleaning substances, disinfecting substances and/or active bleaching substances still present in the used treatment liquid during the current treatment operation. In this respect, these are the essential treatment additives which have to be present in the treatment liquid in a sufficient concentration so that the treatment liquid is able to be re-used.

As claimed in a particularly advantageous development of the invention, after the measuring in particular of the proportion of at least one treatment additive still present in the treatment liquid, the sample is drawn off, for example into a drain.

In a particularly advantageous manner, the method is suitable in the case of a washing device realized as a continuous-batch washing machine in order to re-use used treatment liquid from the continuous-batch washing machine for the pre-wash and/or the final wash. In the case of the pre-wash and where applicable the final wash, used treatment liquid can be re-used in a particularly efficient manner.

In the case of a continuous-batch washing machine, the treatment liquid from the pre-wash, the final wash and/or the rinse operation is re-used at least in a partial manner. Treatment liquids from said treatment steps of the continuous-batch washing machine are particularly suitable for re-use because, as a rule, they contain a large proportion of unused active washing substances.

Preferred exemplary embodiments of the invention are explained below by way of the drawing, in which, in more detail:

FIG. 1 shows a continuous-batch washing machine with a draining device connected downstream in which the washed garments are rinsed and drained,

FIG. 2 shows an alternative exemplary embodiment of a continuous-batch washing machine with a draining device connected downstream for rinsing and draining washed garments,

FIG. 3 shows a third exemplary embodiment of a continuous-batch washing machine with a draining device connected downstream for rinsing and draining washed garments,

FIG. 4 shows a continuous-batch washing machine in which garments are washed and rinsed,

FIG. 5 shows a further exemplary embodiment of the continuous-batch washing machine for washing and rinsing the garments, and

FIG. 6 shows a further alternative exemplary embodiment of a continuous-batch washing machine for washing and rinsing garments.

The invention is described below in conjunction with the wet-treating of garments in industrial washer plants having a continuous-batch washing machine 10 and a draining device 11 (FIGS. 1 to 3).

The continuous-batch washing machine 10 shown in FIG. 1 has a drum 12 which is rotatably drivable about a preferably horizontal axis of rotation. The garments to be washed are conveyed in batches from left to right (with reference to FIG. 1) in the direction of treatment 13 through the rotatably driven drum 12. Several chambers 15 following one after the other in the direction of treatment are formed in the drum 12 by transversely directed partition walls 14. The chambers 15 can be the same size, but can also be different sizes. The continuous-batch washing machine 10 shown in FIG. 1 has four consecutive chambers 15, a first or front chamber 15, when viewed in the direction of treatment 13, forming a pre-wash zone 16. The three chambers 15 following subsequently form a final wash zone 17.

The continuous-batch washing machine 10 shown in FIG. 1 does not have a rinse chamber. The rinsing of the garments is consequently effected in the at least one draining device 11 which is arranged behind the continuous-batch washing machine 10. The draining device 11 shown here is a draining centrifuge. The draining device 11, however, can also be a draining press. The draining device 11 serves for rinsing and draining the garments which are only washed in the continuous-batch washing machine 10.

The continuous-batch washing machine 10 enables a so-called bath exchange in the first chamber 15 of the final wash zone 17, to which end the second chamber 15, when viewed in the direction of treatment 13, has associated therewith a water-impermeable, stationary outer drum 19. The outer drum 19 serves for the purpose of draining off treatment liquid, in the present case pre-wash liquid. Where applicable, the pre-wash liquid can also already be drained off at the end of the pre-wash zone 16, that is to say in the first chamber 15. Said (first) chamber 15 then has associated therewith the outer drum 19. It is also conceivable to associate an outer drum 19 with one or with each further chamber 15 of the final wash zone 17. This applies in particular when the continuous-batch washing machine 10 operates according to the counter flow principle or when another finishing process is to take place in the continuous-batch washing machine 10. At the point where the outer drum 19 is provided, the drum 12 has at least one partially liquid-permeable, for example perforated, drum outer surface.

The draining device 11 shown here has a collecting tank 20 which is formed by the base of the draining device 11. In addition, two separate storage tanks 21 and 22 are provided. Each storage tank 21, 22 is connected to the collecting tank 20 of the draining device 11 by means of a supply line 23. The supply line 23 can be cut off in front of each storage tank 21, 22 by its own valve 24. However, it is also conceivable for the draining device 11 not to have a collecting tank 20. In this case, the treatment liquid passes out of the draining device 11 directly into the storage tank 21 and/or 22.

From the storage tank 21, a draining line 25 leads to the first chamber 15 of the continuous-batch washing machine 10, namely to the single chamber 15 of the pre-wash zone 16. In the exemplary embodiment shown, the draining line 25 is guided to a supply funnel 18 in front of the drum 12 of the continuous-batch washing machine 10.

A second draining line 26 leads from the storage tank 21 to the first chamber 15 of the final wash zone 17.

From the second storage tank 22, only the draining line 25 leads to the supply funnel 18 at the start of the continuous-batch washing machine 10. A valve 27 is associated with each of the draining lines 25, 26. By actuating the valves 27 in a corresponding manner, the storage tanks 21 or 22 are able to be emptied in a targeted manner.

A bypass line 28 branches off in each case from the draining 25, which leads to the supply funnel 18, and from the draining line 26, which leads to the second chamber 15. Said bypass line leads to a pump 33, which supplies treatment liquid through the bypass line 28 to a measuring device 29. A line out 30 leads from the measuring device 29 to a drain (not shown). The bypass line 28, at the point where it branches off from the draining line 25, and at the point where it branches off from the draining line 26, has in each case a valve 31 or 32. By opening and closing the valves 31 or 32 in a corresponding manner, treatment liquid can be branched off from the draining lines 25 or 26 in a targeted manner as a sample. It is also conceivable to realize the pump 33 as a metering pump. In this case the valves 31 and 32 can be omitted because the metering pump branches off a certain amount of treatment liquid from the draining lines 25 or 26 as a sample only when it is operational.

A filter 34 is arranged behind the pump 33, by means of which filter the treatment liquid traversing the bypass line 28 with at least one treatment additive contained therein is able to be filtered. Using said filter 34, fine constituents of the used treatment liquid which impair the measuring process with the measuring device 29 can be filtered out prior to the measuring device 29. This can be effected, for example, by means of micro filtration and/or ultra filtration. It is also conceivable to arrange several filters 34 one behind the other filtering out different substances, in particular substances of different coarseness, from the used treatment liquid. The substances to be filtered out can be lint and other foreign bodies, but also undissolved constituents, preferably used constituents, of at least one treatment additive. In the last-mentioned case, only treatment liquid with non-used treatment additives which is still re-usable for treating subsequent batches of garments with the used treatment liquid reaches the measuring device 29.

The measuring device 29 has at least one sensor (not shown) for measuring the concentration of at least one treatment additive in the treatment liquid branched off by means of the bypass line 28. The measuring device 29 preferably has several different sensors, by way of which various characteristics of the used treatment liquid can be measured, which at least allow reliable conclusions to be drawn as to the proportion of non-used active washing substances in the treatment liquid to be re-used. The sensors, for example, can be a tensiometer for determining the concentration of active washing substances in the treatment liquid. As an alternative to this or in addition, the sensor can be realized as an active chlorine sensor, by way of which active disinfection substances in the treatment liquid can be determined. Finally, it is also conceivable as an alternative to this or in addition to realize a sensor as a so-called H₂O₂ sensor. This enables the content of active bleaching substances in the treatment liquid to be ascertained.

It is also conceivable for the measuring device 29 to have, as an addition or an alternative to this, color sensors, turbidity sensors or means for ascertaining a color change in order to determine the concentration of at least one treatment additive in the used treatment liquid.

The method as claimed in the invention is explained below in conjunction with the device of FIG. 1:

Using the method, at least one treatment additive in the used treatment liquid is measured online during the operation of the continuous-batch washing machine 10 and/or of the draining device 11. In a preferred manner, the amount and/or concentration of the respective treatment additive in the treatment liquid is continuously measured. This consequently occurs “in situ” according to the method as claimed in the invention. Said measuring is effected prior to and/or after the treatment liquid is re-supplied to the continuous-batch washing machine 10, but prior to the start of the treatment of a subsequent batch of garments with the treatment liquid to be re-used.

In the case of the continuous-batch washing machine 10 shown here, the garments pass out of the final wash zone 17 with the final wash liquid into the draining device 11. In this case, the final wash liquid is first of all collected in the collecting tank 20 of the draining device 11 and is then supplied to a storage tank 21 or 22, preferably to the storage tank 21. The garments are then rinsed and drained in the draining device 11. The rinse and draining liquid occurring in this case is also collected in one of the storage tanks 21 or 22, preferably in the storage tank 22.

According to the method as claimed in the invention, not all the used treatment liquid, that is to say final wash liquid and rinse or draining liquid, is measured with regard to the content and the concentration of the treatment additives present therein, rather a small part of the used treatment liquid with at least one treatment additive contained therein is branched off as a sample and only said sample, making up a small part of the treatment liquid, is filtered in the filter 34 and measured in the measuring device 29.

In the case of the exemplary embodiment of FIG. 1, at the start of the removal of the treatment liquid out of the respective storage tank 21 or 22, the relevant valve 31 or 32 is opened for a brief time until a sufficient (small) amount of the used treatment liquid is branched off to form the sample to be measured. After this, the respective valve 31 or 32 is closed again. By means of the pump 33, the sample is pumped through the bypass line 28, first of all through the filter 34 for micro filtration or ultra filtration and then through the measuring device 29. Once the sample has been measured, it leaves the measuring device 29 through the line out 30. The measured sample can then be removed, for example, into a drain. The substance filtered out from the sample by the filter 34 is removed through the line out 49, either to be returned to the treatment liquid or into a drain.

In a preferred manner, a measuring of the at least one treatment additive in the used treatment liquid is effected in a selective manner. To this end, the treatment liquid from the storage tank 21 or from the storage tank 22 is measured separately. In this case, by opening either the valve 31 or 32, a sample is branched off from the treatment liquid from the storage tank 21 or 22 and, as a result, the concentration or the proportion of at least one non-used treatment additive in the treatment liquid from the storage tank 21 or 22 is determined in a targeted manner by the measuring device 29 after the filtering process.

If it has been ascertained during the measuring of the treatment liquid that an amount of the respective treatment additive or of a certain treatment additive contained in the used treatment liquid is no longer sufficient, an additional metering of the respective treatment additive can be effected. This occurs, for example, directly at the supply funnel 18 or when the treatment liquid is supplied into the second chamber 15 by means of the draining line 26. However, it is also conceivable to provide at least one metering device for treatment additives to be additionally metered in the draining line 25 and/or 26 such that in a targeted manner when supplying the used treatment liquid to the supply funnel 18 or to the second chamber 15, the concentration of the at least one treatment additive or of several treatment additives in the used treatment liquid can be increased in the necessary or desired manner.

The measuring device 29 has various sensors, by way of which at least the interfacial tension, the oxidation reduction potential, the alkalinity, the turbidity, the pH value, the conductance, peracetic acid, hydrogen peroxide and/or chlorine in the sample taken from the treatment liquid to be re-used and filtered beforehand is measured.

FIG. 2 shows a further exemplary embodiment of the invention with a continuous-batch washing machine 10 and a following draining device 11 which, in this case, is realized as a draining press. The continuous-batch washing machine 10 corresponds in principle to the one of FIG. 1, which is why identical reference numerals are used for identical parts. The continuous-batch washing machine 10 of FIG. 2 has a total of nine chambers 15. The fourth chamber 15, which has associated therewith an outer drum 19, at the same time defines the end of the pre-wash zone 16 and the start of the final wash zone 17. However, it is conceivable in this case for two chambers 15 to be provided in each case with an outer drum 19 such that the last chamber of the pre-wash zone 16 and the first chamber of the final wash zone 17 have their own outer drums 19.

In the exemplary embodiment shown, two storage tanks 50, 51 are arranged downstream of the draining press 11. The storage tank 50 receives treatment liquid from the final wash zone 17, which treatment liquid, together with the garments to be washed, is transferred from the continuous-batch washing machine 10 into the draining press 11 and is only separated here from the garments to be washed. The storage tank 51 receives rinse liquid which arises in the draining press 11 when the garments to be washed are rinsed. Once the garments are rinsed, the same are drained in the draining press 11, a large portion of the detergent solution bound in the garments being pressed out of the garments. The draining liquid arising in this case is drawn off via the outlet 52, for example to a drain. Where applicable, the draining liquid can also be collected in one of the storage tanks 50 or 51 or in a separate storage tank. The storage tank 51 is connected to a preparation tank 54 by means of a supply line 53. Treatment liquid to be re-used can be supplied from the preparation tank 54 through a closable outlet 55 via an inlet funnel 56 to the first chamber 15 of the pre-wash zone 16 together with a new batch of garments to be washed. The tank 50 is connected to the fourth chamber 15 at the start of the final wash zone 17 by means of a supply line 57. In addition, the storage tank 50 is connected to the supply line 53 to the preparation tank 54 by way of a blockable bypass line 58.

The outer drum 19 of the fourth chamber 15 at the end of the pre-wash zone 16 and at the start of the final wash zone 17 has associated therewith a sample-taking-line 59 which is provided with a valve and leads to a pump 33. A coarse filter 60 follows the pump 33 and then a filter 34 for micro filtration or ultra filtration of the sample of the treatment liquid to be re-used. The filter residue filtered out at the filter 34 is guided via a secondary line 61 past the measuring device 29 to a return line 62 which leads to the fourth chamber 15 of the continuous-batch washing machine 10.

The filtered sample of the treatment liquid to be re-used is supplied to the measuring device 29 which follows the filter 34. The measuring device 29 carries out various measurements on the filtered sample, in particular it determines the remaining content of unused active washing substances in the treatment liquid to be re-used. The measuring device 29 preferably carries out the same measurements as mentioned in conjunction with the previous description of the continuous-batch washing machine 10 of FIG. 1.

From the preparation tank 54, a further sample-taking-line 63 leads to a second pump 33 with a coarse filter 60 following thereafter, a filter 34 for micro filtration or ultra filtration and a measuring device 29 following thereafter which can carry out the same measurements as the measuring device 29 for the sample from the fourth chamber 15. The measured sample can be returned to the preparation tank 54 by means of a return line 81. A secondary line 64 opens out into the return line 81, filter residue arising at the filter 34 being returnable to the preparation tank 54 by means of the secondary line 64.

Whereas in the exemplary embodiment shown, a sample from the fourth chamber 15 of the continuous-batch washing machine 10 and from the preparation tank 54 has in each case associated therewith its own pump 33 with a coarse filter 60, a filter 34 and a measuring device 29, it is also conceivable to provide only one pump 33, one coarse filter 60, one filter 34 and one measuring device 29 in order to measure or to test in an alternating manner a sample from the fourth chamber 15 of the continuous-batch washing machine 10 or from the preparation tank 54.

The method as claimed in the invention runs in conjunction with the exemplary embodiment of FIG. 2 as follows:

In principle, the method of the exemplary embodiment of FIG. 2 corresponds to the method described in conjunction with the exemplary embodiment of FIG. 1.

This applies in particular to the design of the measuring device 29 and the measurements that can be carried out therewith.

The method of the continuous-flow washing machine 10 shown in FIG. 2 with the draining press 11 differs from that of FIG. 1 mainly in that the treatment liquid to be re-used is supplied either to the fourth chamber 15 at the start of the final wash zone 17 of the continuous-batch washing machine 10 or to the preparation tank 54. As an alternative to this or in addition, final wash liquid and/or rinse liquid can be supplied as treatment liquid to be re-used to the preparation tank 54 or to the fourth chamber from the relevant storage tank 50, 51. Consequently, where necessary final wash liquid and rinse liquid can be mixed in the preparation tank 54 or the fourth chamber 15 before they are supplied via the inlet funnel 56 to the pre-wash zone 16 or via the fourth chamber 15 to the final wash zone as treatment liquid to be re-used.

The liquid to be re-used is measured as claimed in the invention in the preparation tank 54 or in the fourth chamber at the start of the final wash zone 17. In this connection, this is treatment liquid which is directly supplied for re-use and has been warmed or heated up to the required temperature. As a result, the treatment liquid is measured in a state or stage in which it is situated before it is moved into contact with the treatment liquid to be re-used with the next batch of garments to be washed. The treatment liquid to be re-used which is filled into the fourth chamber 15 at the start of the final wash zone 17 as well as the treatment liquid in the preparation tank 54 are branched off directly from the fourth chamber 15 or the preparation tank 54 as a small sample and are then subject to the desired analysis or measuring process by the measuring device 29 after coarse filtration and micro filtration. In this case, the treatment liquids from the first chamber 15 of the final wash zone 17 and from the preparation tank 54 are measured separately in each case by their own measuring device 29 such that the measuring processes can take place at the same time next to one another (in parallel). However, consecutive, separate measuring processes are also conceivable, for which purpose only one single measuring device 29 is necessary.

In the case of the exemplary embodiment of FIG. 2 also, the measuring process serves, among other things, for the purpose of ascertaining whether the used treatment liquid still has enough remaining active washing substances in order to be re-used. If this should be the case, corresponding additional metering and then re-measuring of the content of active washing substances in the treatment liquid to be re-used are carried out in order to test whether the additional metering of fresh treatment liquid has been carried out to a sufficient extent. Where applicable, another additional metering and a repeated measuring process are carried out to test whether the additional metering is sufficient.

FIG. 3 shows a further exemplary embodiment of the invention. Said exemplary embodiment only differs from the exemplary embodiment of FIG. 2 in that all the treatment liquid to be re-used is filtered and not only a small part of the treatment liquid to be re-used is tested by the respective measuring device 29 in particular with regard to the content of unused active washing substances.

Used treatment liquid is directed out of the pre-wash zone 16 on the outer surface 19 of the fourth chamber 15 to a buffer tank 66 by means of a supply line 65. The final wash liquid to be re-used as treatment liquid, and where applicable the rinse liquid from the draining device 11, pass via a supply line 67 into a buffer tank 68. The two buffer tanks 66, 68 have a common pump 69 arranged downstream. The treatment liquid can be supplied to the pump 69 in a selective manner from the buffer tank 66 or 68. The pump 69 pumps the treatment liquid through a coarse filter 60. From there, the coarsely filtered treatment liquid to be re-used is pumped by a pump 33 through the filter 34 for micro filtration and/or ultra filtration of the treatment liquid to be re-used. The treatment liquid filtered in a coarse and fine manner by the filters 60 and 34 is then directed either into a buffer tank 70 following thereafter or into a buffer tank 71. Filtered treatment liquid from the buffer tank 66 passes into the buffer tank 70, while filtered treatment liquid from the buffer tank 68 is buffered in the buffer tank 71. Filtered treatment liquid to be re-used from the buffer tank 70 passes into the preparation tank 54 via a supply line 72. Via a further supply line 73, filtered treatment liquid to be re-used from the buffer tank 71 is directed, preferably pumped, to the fourth chamber 15 of the continuous-batch washing machine 10 to the start of the final wash zone 17.

In the case of the exemplary embodiment of FIG. 3, the method as claimed in the invention runs just as in the case of the exemplary embodiment in FIG. 2. The method of FIG. 3 differs from the method of FIG. 2 only in that all the treatment liquid to be re-used, that is used treatment liquid from the pre-wash zone 16 or treatment liquid from the draining device 11, is filtered in a coarse manner by the coarse filter 60 and is subject to micro filtration or ultra filtration by the filter 34 following thereafter.

FIG. 4 shows a continuous-batch washing machine 35, only the three consecutive treatment zones of which, namely the pre-wash zone 36, the final wash zone 37 and the rinse zone 38, are shown in a symbolic manner. In principle, the continuous-batch washing machine 35 is designed in the same manner as the continuous-batch washing machine 10 and, in particular, has a drum which is rotatably drivable about a horizontal axis of rotation.

Because the continuous-batch washing machine 35 has a rinse zone 38, only one draining operation of the garments washed and rinsed in the continuous-batch washing machine 35 takes place in the draining device (not shown in FIG. 4) behind the continuous-batch washing machine 35. The draining device can be realized in the manner of a centrifuge or a garment press.

In the case of the continuous-batch washing machine 35 shown here, the treatment liquid from the respective zone can be separated from the garments by means of a draining line 39 by correspondingly placed (not shown in FIG. 4), stationary outer drums. By means of valves 40, used treatment liquid originating from one or several zones can be supplied to a return line 41. The return line 41 makes it possible to direct the used treatment liquid with the at least one treatment additive still present therein back to a zone of the continuous-batch washing machine 35. By means of valves 32 at the end of the return line 41, it is possible to supply used treatment liquid with at least one treatment additive in a targeted manner to the pre-wash zone 36, the final wash zone 37 or the rinse zone 38.

In the case of the continuous-batch washing machine 35 shown here, where applicable used treatment liquid with at least one treatment additive can be diverted from all zones and supplied again in a targeted manner to the following wet treatment operation of at least one selected zone. However, it is also conceivable to return used pre-wash liquid with at least one treatment additive still present therein at the end of the pre-wash zone 36, that is to say in the last chamber of the same, or at the start of the final wash zone, namely the first chamber of the same, by means of an outer drum, preferably to the start of the pre-wash zone 36. It is equally conceivable to re-use only the final wash liquid and/or the rinse liquid by re-supplying it to the continuous-batch washing machine 35, in particular to the pre-wash zone 36, by means of the draining line 39 and the return line 41.

A circulating pump 43 in the return line 41 serves for circulating the treatment liquid to be re-used with at least one treatment additive present therein. No storage tanks for used treatment liquid are shown in FIG. 4. However, it is completely conceivable, as in the case of the previous exemplary embodiments, to provide at least one storage tank, in a preferred manner such that the draining line 39 opens out into the storage tank and the return line 41 proceeds from the bottom of the at least one storage tank.

A bypass line 44 is also provided in the exemplary embodiment of FIG. 4. Said bypass line branches off from the draining line 39 or from the return line 41, at a branch 48. A pump 45, a filter 46 following thereafter and a measuring device 47 are also arranged in the bypass line 44. The pump 45, in this case, is realized as a metering pump such that no valve needs to be present at the branch 48 of the bypass line 44 from the return line 41. Only when the metering pump is operational does it branch off a sample of the used treatment liquid of the at least one treatment additive still present therein from the returned treatment liquid in the return line 41. The amount of the small part stream, namely of the sample, branched off from the main stream of the used treatment liquid is determined by a corresponding running time of the metering pump. The filter 46 and the measuring device operate just as the filter 34 and the measuring device 29 of the previous exemplary embodiments.

The method runs in the case of the arrangement of FIG. 4 in principle precisely as described in conjunction, in particular, with the exemplary embodiment of FIG. 1. The pump 45, which is realized as a metering pump, branches off from the main stream of the used treatment liquid a small amount serving as a sample, which is first of all filtered and is then tested in the measuring device 47 for the at least one active treatment additive still present therein, “in situ” during the operation of the continuous-batch washing machine 35.

The used treatment liquid to be tested with at least one treatment additive in particular of active washing substances can be pre-wash liquid, final wash liquid or rinse liquid, but can also be a combination of several of the named treatment liquids or of all of the named treatment liquids.

Like FIG. 4, FIG. 5 shows a continuous-batch washing machine 35 for pre-washing, final washing, rinsing and where applicable finishing of the garments to be washed. FIG. 5 shows all thirteen chambers 15 of the continuous-batch washing machine 35 in the exemplary embodiment shown. The continuous-batch washing machine 35 is followed by a draining device 74 which in FIG. 5 is a draining press.

The first four chambers 15, when viewed in the direction of treatment of the continuous-batch washing machine 35, form the pre-wash zone 36. The following five to nine chambers 15 form the final wash zone 37. Chambers 15 ten to twelve include the rinse zone 38.

The last, thirteenth chamber 15 of the continuous-batch washing machine 35 shown in FIG. 5 forms a finishing zone 75.

The fourth, fifth, ninth, tenth, twelfth and thirteenth chambers 15 of the continuous-batch washing machine 35 of FIG. 5 are provided with outer drums 19 for the removal of used treatment liquids. Rinse liquid from the rinse zone 38 is removed into a storage tank 76 at the end of said rinse zone by means of the outer drum 19 of the twelfth chamber 15. The liquid separated off from the drained garments by the draining device 74 is collected in the separate storage tank 77.

A supply line 78 to the fifth chamber 15 at the start of the final wash zone 37 leads from the storage tank 76. A separate supply line 79 to the preparation tank 54 at the inlet funnel 56 of the continuous-batch washing machine 35 leads from the storage tank 77. A blockable bypass line 80 connects the storage tank 76 to the supply line 79 such that, as an alternative, used rinse liquid from the storage tank 76 is able to be supplied to the preparation tank 54.

In the case of the continuous-batch washing machine 35, small amounts of the treatment liquid to be re-used can be branched off as a sample from the first chamber 15 of the final wash zone 37 (that is the fifth chamber of the continuous-batch washing machine 35 shown in FIG. 5) and from the preparation tank 54 and after the coarse filter 60 and the subsequent micro filter or ultra filter 34 can be supplied to a measuring device 29. To this end, a sample-taking line 59 is guided from the fifth chamber 15 of the continuous-batch washing machine 35 to the pump 33 as in the case of the exemplary embodiment of FIGS. 2 and 3. The same applies to the sample-taking line 63 which branches off from the preparation tank 54. Because as regards the sample taking, sample filtration and measuring, the exemplary embodiment of FIG. 5 matches the exemplary embodiment of FIG. 2, identical reference numerals are used for identical parts. The method of the sample taking, filtration and measuring is also the same in the exemplary embodiment of FIG. 5 as for the exemplary embodiment of FIG. 2 such that, once again, reference is made to the explanations for the method of the exemplary embodiment of FIG. 2.

The treatment liquid to be re-used from the rinse zone 38 and from the draining device 74 is not filtered in the case of the exemplary embodiment of FIG. 5 and is also not tested or measured with regard, in particular, to the content of non-used active washing substances. In this connection, in the case of the exemplary embodiment of FIG. 5, only small samples of the treatment liquid to be re-used from the first chamber 15 of the final wash zone 37, that is from the fifth chamber 15 behind the inlet funnel 56, or from the preparation tank 54 are measured after the multiple filtering with various filter sizes and where applicable treatment additives such as, in particular, active washing substances are additionally metered.

FIG. 6 shows an exemplary embodiment of the invention which differs from that of FIG. 5 only in that coarse filtering and then micro filtering or ultra filtering of all the used treatment liquid are effected prior to re-use and prior to returning into the preparation tank 54 or into the first chamber 15 of the final wash zone 37. For the rest, the exemplary embodiment of FIG. 6 corresponds to that of FIG. 5, once again identical reference numerals being used for identical parts.

The coarse filtration and subsequent micro filtration or ultra filtration of the used treatment liquid from the pre-wash zone 36 and from the final wash zone 37 are effected just as in the case of the exemplary embodiment of FIG. 3. The identical reference numerals from FIG. 3 are used for identical parts. Accordingly, used treatment liquid from the pre-wash zone 36 is stored in the buffer tank 66, whilst the buffer tank 68 accommodates used rinse liquid from the rinse zone 38. Accordingly, in this case too used treatment liquid, that is pre-wash liquid, from the buffer tank 66 or rinse liquid from the buffer tank 68, is supplied in a selective or alternating manner to the pump 69 and is pumped by said pump through the coarse filter 60. The coarsely filtered used treatment liquid is pumped through the filter 34 for micro filtration or ultra filtration by the connecting pump 33. The coarsely and finely filtered used treatment liquid is then stored temporarily in either the buffer tank 70 or in the buffer tank 71. Filtered pre-wash liquid is stored temporarily in the buffer tank 70 and filtered rinse liquid is buffered in the buffer tank 71. Coarsely-filtered and micro filtered treatment liquid is pumped via the supply line 72 from the buffer tank 70 to the preparation tank 54 at the start of the continuous-batch washing machine 35. Coarsely-filtered and micro filtered treatment liquid, in particular rinse liquid, is pumped from the buffer tank 71 via the supply line 73 to the fifth chamber 15, namely the first chamber of the final wash zone 37.

The removing of small samples from the final wash liquid to be re-used at the start of the final wash zone 17 and the treatment liquid to be re-used in the preparation tank 54 is removed, coarsely filtered and after micro filtration is subject to various measurements as in the case of the exemplary embodiment in FIG. 5. In particular, the proportion of non-used active washing substances in the treatment liquid to be re-used is determined. The measuring device 29 preferably has different sensors, by way of which the interfacial tension, the oxidation reduction potential, the alkalinity, the turbidity, the pH value, the conductance, the peracetic acid content, hydrogen peroxide and/or chlorine of the sample to be re-used taken from the continuous-batch washing machine 35 are determined. The sample is preferably taken from the treatment liquid to be measured or to be analyzed when said treatment liquid is at the temperature necessary for the respective treatment of the garments to be washed, that is to say has been correspondingly heated up or warmed up. As a result, the measuring of the sample is effected in a state in which the sample is for the treatment of the garments to be washed. When the result of the measuring of the filtered sample shows that an additional metering of at least one treatment additive is necessary, an additional metering and a subsequent new sample removal with a repeated measuring of said new sample are effected at least once.

The invention has been described above in conjunction with the wet-treating, namely the washing and draining of garments to be washed in industrial washers. The invention is also suitable, however, for washing garments in domestic washing machines and for washing arbitrary other objects, for example for rinse machines, for the cleaning of containers, in particular the cleaning of bottles, for wash facilities, vehicle washers, for cleaning installations, for example conveyors, in food engineering and similar purposes. The use of the method as claimed in the invention is consequently not restricted to the described applications, in particular not to the wet-treating of garments.

LIST OF REFERENCES

-   -   10 Continuous-batch washing machine     -   11 Draining device     -   12 Drum     -   13 Treatment direction     -   14 Partition wall     -   15 Chamber     -   16 Pre-wash zone     -   17 Final wash zone     -   18 Supplying funnel     -   19 Outer drum     -   20 Collecting tank     -   21 Storage tank     -   22 Storage tank     -   23 Supply line     -   24 Valve     -   25 Draining line     -   26 Draining line     -   27 Valve     -   28 Bypass line     -   29 Measuring device     -   30 Line out     -   31 Valve     -   32 Valve     -   33 Pump     -   34 Filter     -   35 Continuous-batch washing machine     -   36 Pre-wash zone     -   37 Final wash zone     -   38 Rinse zone     -   39 Draining line     -   40 Valve     -   41 Return line     -   42 Valve     -   43 Circulating pump     -   44 Bypass line     -   45 Pump     -   46 Filter     -   47 Measuring device     -   48 Branch     -   49 Line out     -   50 Storage tank     -   51 Storage tank     -   52 Outlet     -   53 Supply line         -   54 Preparation tank     -   55 Outlet     -   56 Inlet funnel     -   57 Supply line     -   58 Bypass line     -   59 Sample-taking line     -   60 Coarse filter     -   61 Secondary line     -   62 Return line     -   63 Sample-taking line     -   64 Secondary line     -   65 Supply line     -   66 Buffer tank     -   67 Supply line     -   68 Buffer tank     -   69 Pump     -   70 Buffer tank     -   71 Buffer tank     -   72 Supply line     -   73 Supply line     -   74 Draining device     -   75 Finishing zone     -   76 Storage tank     -   77 Storage tank     -   78 Supply line     -   79 Supply line     -   80 Bypass line     -   81 Return line 

1. A method for wet-treating objects using a washing device, wherein the objects are treated with a treatment liquid having at least one treatment additive and the treatment liquid is measured, wherein a sample is branched off from the treatment liquid and only said sample is measured.
 2. The method as claimed in claim 1, wherein the sample is filtered prior to the measuring.
 3. The method as claimed in claim 1, wherein the sample is branched off from the treatment liquid after the treatment liquid is used to treat the objects and prior to re-use of the used treatment liquid.
 4. The method as claimed in claim 3, wherein the sample is taken from the treatment liquid to be re-used once said treatment liquid has been returned into the washing device and/or into a preparation tank for the provision of the treatment liquid to be re-used.
 5. The method as claimed in claim 1, wherein during the operation of the washing device, the sample is branched off from the treatment liquid used and to be re-used, the sample is filtered, and then the sample is measured.
 6. The method as claimed in claim 5, wherein constituents of the treatment liquid to be re-used filtered out from the sample of the treatment liquid to be re-used prior to the measuring, are re-supplied to the treatment liquid to be re-used, prior to and/or in the washing device.
 7. The method as claimed in claim 1, wherein the remaining proportion of the at least one treatment additive in the treatment liquid to be re-used is determined and if a minimum proportion of the at least one treatment additive in the treatment liquid is undershot, a targeted additional metering of the relevant treatment additive is effected.
 8. The method as claimed in claim 7, wherein after the additional metering or after each additional metering of the treatment liquid to be re-used, once again a sample is taken, the sample is filtered, and then the sample is measured.
 9. The method as claimed in claim 1, wherein a proportion of the active cleaning substances, disinfecting substances and/or active bleaching substances still present in the treatment liquid after the treatment liquid is used to treat the objects is determined by measuring the previously filtered sample.
 10. The method as claimed in claim 1, wherein the sample is drawn off after the measuring process.
 11. The method as claimed in claim 1, wherein in the case of a washing device that is a continuous-batch washing machine, the used treatment liquid is re-used for a pre-wash and/or a final wash.
 12. The method as claimed in claim 11, wherein the used treatment liquid is re-used for the pre-wash, the final wash and/or for rinsing.
 13. The method as claimed in claim 2, wherein the sample is filtered by micro filtration.
 14. The method as claimed in claim 10, wherein the sample is drawn off after the measuring process into a drain.
 15. A method for wet-treating objects preferably using a washing device, comprising the steps of: treating the objects with a treatment liquid having at least one treatment additive; branching a sample off from the treatment liquid; and measuring only the sample in regard to the concentration of the at least one treatment additive in the sample, wherein the concentration of the at least one treatment additive in the sample is used to indicate the concentration of the at least one treatment additive still present in the treatment liquid used. 